The proposed research is aimed at the progressive development of empirically based models of mother-infant dyad development. Characteristics of the mother and infant at birth and lying-in, such as maternal attitudes and infant behavior patterns, as well as biographical factors will form the initial network of variables to be explored. The focus of mother-infant dyad development is centered on the first days after birth till 4-6 weeks thereafter. This formative period has been selected for intense study because of its potential relevance to early prevention of mental disorders. The proposed research is organized around three interdependent and overlapping stages: 1) psychometrics (to refine the measurement properties of the psychological tools used in the research, 2) data analysis (to systematically explore the network of relationships among variables, and 3) model building (to construct a model(s) which are congruent with the empirical configuration of data). These three stages will roughly parallel the three years of requested support. In the first year a battery of attitudinal, perception and interview data will be collected from mothers. Infants will be examined using the Brazelton Infant Scale. Both mothers and infants will be videotaped together in a variety of interactive situations. All of these data will be examined from a psychometric point of view.